oj.uz

Submission #1105287

# Submission time Handle Problem Language Result Execution time Memory
1105287 2024-10-26T03:28:32 Z Zero_OP Xylophone (JOI18_xylophone) C++17
100 / 100
 70 ms 98632 KB 
#include <bits/stdc++.h>
#ifndef LOCAL
    #include <xylophone.h>
#endif // LOCAL

using namespace std;

const int MAX = 5e3 + 5;

#ifdef LOCAL
int A[MAX];

int query(int s, int t){
    return *max_element(A + s, A + t + 1) - *min_element(A + s, A + t + 1);
}

void answer(int i, int a){
//    cout << i << " : " << a << '\n';
    if(A[i] != a){
        cout << "WRONG ANSWER\n";
        exit(0);
    }
}
#endif

int memo[MAX][MAX];

int ask(int l, int r){
    assert(l <= r);
    if(l == r) return 0;
    if(memo[l][r] != 0) return memo[l][r];
    return memo[l][r] = query(l, r);
}

void solve(int N){
    memset(memo, 0, sizeof(memo));
    if(N == 1){
        answer(1, 1);
        answer(2, 2);
        return;
    }
    int l = 1, r = N, R = -1;
    while(l <= r){
        int mid = l + r >> 1;
        if(ask(1, mid) == N - 1) R = mid, r = mid - 1;
        else l = mid + 1;
    }

    l = 1, r = R - 1;
    int L = 1;
    while(l <= r){
        int mid = l + r >> 1;
        if(ask(mid, R) == N - 1) L = mid, l = mid + 1;
        else r = mid - 1;
    }

    //find L, R that A[L] = 1, A[R] = N
    vector<int> a(N + 1);
    a[L] = 1;
    a[R] = N;

    if(L > 1) a[L - 1] = 1 + ask(L - 1, L);
    if(R < N) a[R + 1] = N - ask(R, R + 1);

    vector<bool> used(N + 1);
    used[1] = used[N] = true;

    auto casework = [&](int x, int y, int nextTwo, int nextThree){
        int case1 = x - nextTwo;
        if(max({case1, x, y}) - min({case1, x, y}) == nextThree) return case1;

        int case2 = x + nextTwo;
        if(max({case2, x, y}) - min({case2, x, y}) == nextThree) return case2;

        cout << x << ' ' << y << ' ' << nextTwo << ' ' << nextThree << '\n';
        assert(false);
    };

    for(int i = L - 2; i >= 1; --i){
        int delta = ask(i, i + 1);
        if(a[i + 1] - delta < 0 || used[a[i + 1] - delta]) a[i] = a[i + 1] + delta;
        else if(a[i + 1] + delta > N || used[a[i + 1] + delta]) a[i] = a[i + 1] - delta;
        else a[i] = casework(a[i + 1], a[i + 2], delta, ask(i, i + 2));

        used[a[i]] = true;
    }

    for(int i = R + 2; i <= N; ++i){
        int delta = ask(i - 1, i);
        if(a[i - 1] - delta < 0 || used[a[i - 1] - delta]) a[i] = a[i - 1] + delta;
        else if(a[i - 1] + delta > N || used[a[i - 1] + delta]) a[i] = a[i - 1] - delta;
        else a[i] = casework(a[i - 1], a[i - 2], delta, ask(i - 2, i));

        used[a[i]] = true;
    }

    if(L + 1 < R){
        a[L + 1] = 1 + ask(L, L + 1);
        for(int i = L + 2; i < R; ++i){
            int delta = ask(i - 1, i);
            if(a[i - 1] - delta < 0 || used[a[i - 1] - delta]) a[i] = a[i - 1] + delta;
            else if(a[i - 1] + delta > N || used[a[i - 1] + delta]) a[i] = a[i - 1] - delta;
            else a[i] = casework(a[i - 1], a[i - 2], delta, ask(i - 2, i));

            used[a[i]] = true;
        }
    }

    for(int i = 1; i <= N; ++i){
        answer(i, a[i]);
    }
}

#ifdef LOCAL
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
int random(int l, int r){ return uniform_int_distribution<int>(l, r)(rng); }

int main(){
    srand(time(nullptr));

    for(int itest = 1; itest <= 300; ++itest){
        int N = random(2, 30);
        iota(A + 1, A + 1 + N, 1);
        shuffle(A + 1, A + 1 + N, rng);

//        int N = 6;
//        vector<int> vec = {1, 6, 5, 3, 2, 4};
//        copy(vec.begin(), vec.end(), A + 1);

        int pos1 = -1, posN = -1;
        for(int i = 1; i <= N; ++i){
            if(A[i] == 1) pos1 = i;
            if(A[i] == N) posN = i;
        }

        if(pos1 > posN){
            swap(pos1, posN);
            swap(A[pos1], A[posN]);
        }

        cout << "The permutation length N : ";
        for(int i = 1; i <= N; ++i) cout << A[i] << ' '; cout << '\n';
        solve(N);
        cout << "Passed\n";
    }

    return 0;
}
#endif // LOCAL

Compilation message

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:44:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   44 |         int mid = l + r >> 1;
      |                   ~~^~~
xylophone.cpp:52:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   52 |         int mid = l + r >> 1;
      |                   ~~^~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 98384 KB Output is correct
2 Correct 13 ms 98384 KB Output is correct
3 Correct 13 ms 98384 KB Output is correct
4 Correct 15 ms 98384 KB Output is correct
5 Correct 14 ms 98384 KB Output is correct
6 Correct 15 ms 98384 KB Output is correct
7 Correct 16 ms 98280 KB Output is correct
8 Correct 14 ms 98384 KB Output is correct
9 Correct 15 ms 98288 KB Output is correct
10 Correct 14 ms 98552 KB Output is correct
11 Correct 15 ms 98384 KB Output is correct
12 Correct 15 ms 98384 KB Output is correct
13 Correct 15 ms 98384 KB Output is correct
14 Correct 14 ms 98384 KB Output is correct
15 Correct 14 ms 98224 KB Output is correct

Subtask #2
36.0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 98384 KB Output is correct
2 Correct 13 ms 98384 KB Output is correct
3 Correct 13 ms 98384 KB Output is correct
4 Correct 15 ms 98384 KB Output is correct
5 Correct 14 ms 98384 KB Output is correct
6 Correct 15 ms 98384 KB Output is correct
7 Correct 16 ms 98280 KB Output is correct
8 Correct 14 ms 98384 KB Output is correct
9 Correct 15 ms 98288 KB Output is correct
10 Correct 14 ms 98552 KB Output is correct
11 Correct 15 ms 98384 KB Output is correct
12 Correct 15 ms 98384 KB Output is correct
13 Correct 15 ms 98384 KB Output is correct
14 Correct 14 ms 98384 KB Output is correct
15 Correct 14 ms 98224 KB Output is correct
16 Correct 15 ms 98384 KB Output is correct
17 Correct 17 ms 98408 KB Output is correct
18 Correct 19 ms 98384 KB Output is correct
19 Correct 21 ms 98384 KB Output is correct
20 Correct 21 ms 98296 KB Output is correct
21 Correct 21 ms 98384 KB Output is correct
22 Correct 23 ms 98232 KB Output is correct
23 Correct 18 ms 98384 KB Output is correct
24 Correct 18 ms 98396 KB Output is correct
25 Correct 19 ms 98384 KB Output is correct
26 Correct 21 ms 98384 KB Output is correct
27 Correct 20 ms 98384 KB Output is correct
28 Correct 21 ms 98384 KB Output is correct
29 Correct 20 ms 98396 KB Output is correct
30 Correct 19 ms 98384 KB Output is correct

Subtask #3
53.0 / 53.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 98384 KB Output is correct
2 Correct 13 ms 98384 KB Output is correct
3 Correct 13 ms 98384 KB Output is correct
4 Correct 15 ms 98384 KB Output is correct
5 Correct 14 ms 98384 KB Output is correct
6 Correct 15 ms 98384 KB Output is correct
7 Correct 16 ms 98280 KB Output is correct
8 Correct 14 ms 98384 KB Output is correct
9 Correct 15 ms 98288 KB Output is correct
10 Correct 14 ms 98552 KB Output is correct
11 Correct 15 ms 98384 KB Output is correct
12 Correct 15 ms 98384 KB Output is correct
13 Correct 15 ms 98384 KB Output is correct
14 Correct 14 ms 98384 KB Output is correct
15 Correct 14 ms 98224 KB Output is correct
16 Correct 15 ms 98384 KB Output is correct
17 Correct 17 ms 98408 KB Output is correct
18 Correct 19 ms 98384 KB Output is correct
19 Correct 21 ms 98384 KB Output is correct
20 Correct 21 ms 98296 KB Output is correct
21 Correct 21 ms 98384 KB Output is correct
22 Correct 23 ms 98232 KB Output is correct
23 Correct 18 ms 98384 KB Output is correct
24 Correct 18 ms 98396 KB Output is correct
25 Correct 19 ms 98384 KB Output is correct
26 Correct 21 ms 98384 KB Output is correct
27 Correct 20 ms 98384 KB Output is correct
28 Correct 21 ms 98384 KB Output is correct
29 Correct 20 ms 98396 KB Output is correct
30 Correct 19 ms 98384 KB Output is correct
31 Correct 36 ms 98384 KB Output is correct
32 Correct 38 ms 98384 KB Output is correct
33 Correct 48 ms 98384 KB Output is correct
34 Correct 61 ms 98384 KB Output is correct
35 Correct 60 ms 98304 KB Output is correct
36 Correct 53 ms 98384 KB Output is correct
37 Correct 44 ms 98384 KB Output is correct
38 Correct 49 ms 98384 KB Output is correct
39 Correct 64 ms 98488 KB Output is correct
40 Correct 67 ms 98392 KB Output is correct
41 Correct 64 ms 98384 KB Output is correct
42 Correct 53 ms 98384 KB Output is correct
43 Correct 46 ms 98632 KB Output is correct
44 Correct 51 ms 98384 KB Output is correct
45 Correct 67 ms 98384 KB Output is correct
46 Correct 64 ms 98484 KB Output is correct
47 Correct 67 ms 98488 KB Output is correct
48 Correct 67 ms 98384 KB Output is correct
49 Correct 68 ms 98384 KB Output is correct
50 Correct 62 ms 98384 KB Output is correct
51 Correct 60 ms 98384 KB Output is correct
52 Correct 68 ms 98492 KB Output is correct
53 Correct 63 ms 98384 KB Output is correct
54 Correct 62 ms 98384 KB Output is correct
55 Correct 63 ms 98384 KB Output is correct
56 Correct 61 ms 98444 KB Output is correct
57 Correct 59 ms 98384 KB Output is correct
58 Correct 51 ms 98384 KB Output is correct
59 Correct 63 ms 98384 KB Output is correct
60 Correct 70 ms 98496 KB Output is correct